by Cindy L.A. Jones, Ph.D.
Cancer treatments are a paradox, on one hand delivering powerful toxicity to a tumor, but on the other spreading toxicity to the rest of the body. The side effects of such treatments may cause death even before the cancer does. Biological response modifiers (BRMs) are compounds that have a unique effect on physiology and can reduce the side effects of cancer treatments, while at the same time increasing their effectiveness.
A BRM repairs damage to the body rather than targeting a pathogenic
agent such as cancer. It typically acts by stimulating the immune system to
restore optimal function. Many diseases and infections as well as AIDS result
from immune surveillance failure. Because chemotherapy compromises the immune
system, people receiving cancer treatments run an especially high risk of contracting
and dying of infections.
Cytokines, hormones naturally produced in the body, promote immunity
and are often used clinically as BRMs--to treat disease, fight viral infections
and augment chemotherapy. Three pharmaceutical cytokines currently in use include
colony-stimulating factors that reduce the chance of infection and thus the
need for antibiotics by stimulating bone marrow to produce more white blood
cells; interferons that stimulate macrophages to ingest foreign particles and
help the body produce antiviral chemicals; and interleukins that stimulate growth
and activation of white blood cells. The therapeutic use of these cytokines,
called immunotherapy, as a cancer treatment both with and without standard anti-cancer
drugs is marginally successful. Side effects such as depression, nausea and
chest pain, however, can limit the effectiveness of some pharmaceutical cytokines.
Many herbs have long been known to affect the immune system, but
only recently have scientists considered them as possible BRMs and adjunct cancer
therapies. Such herbs often prompt the body's cells to secrete cytokines, which
then enhance the immune response. The most promising of these herbs include
black cumin, mistletoe, ginseng, astragalus, green tea, echinacea and garlic.
Black Cumin
Black cumin (Nigella sativa) is related to a common garden
flower that goes by several names including cinnamon flower, nutmeg flower and
love-in-a-mist. In the Mediterranean and Middle East where nigella seeds are
traditionally used, it is also referred to as black seed and is used for a variety
of ailments including upper respiratory conditions, headaches, cancer, stomachaches
and jaundice. Nigella seeds are traditionally eaten alone or ground with honey.
Nigella is considered a BRM because studies show extracts from
the seeds are toxic to cancer cells and, in mice, prevent blood cell toxicity
caused by the anti-cancer drug cisplatin.1 The active components
of nigella seeds are the volatile oils thymoquinoline and dithymoquinone, both
of which inhibit tumor cells in laboratory experiments--even tumor cells resistant
to anti-cancer drugs.2 A recent cell study conducted at the International
Immuno-Biology Research Laboratory in South Carolina showed that when incubated
with nigella extract, cancer cells were unable to produce fibroblast growth
factor and the protein collagenase, both necessary for blood-vessel growth into
the tumor.3 Without a blood supply, a tumor cannot grow.
Nigella also stimulates the immune system, as shown in an experiment
conducted with human lymphocytic white blood cells. Cells treated with nigella-seed
proteins produced greater amounts of cytokines, specifically interleukin-1-beta
and tumor necrosis factor alpha.4 How and if this is important to
treating cancer is not yet established.
Another recent experiment indicates that thymoquinone may also
prevent some toxic side effects of cancer treatments. Scientists from King Saud
University in Saudi Arabia found that mice pretreated with thymoquinone were
protected from carbon tetrachloride-induced liver toxicity. Carbon tetrachloride
is a toxin that in small amounts can kill by causing the liver and kidney to
atrophy. Liver toxicity was assessed by measuring the release of liver enzymes
in the blood. Thymoquinone also demonstrated antioxidant activity, which may
be how it protects the liver.5
According to U.S.D.A. Phytochemical and Ethnobotanical Databases
compiled by James Duke, Ph.D., nigella seed also contains limonene.6
Found in high amounts in lavender, limonene is being investigated for use as
a treatment for some types of cancer.7
Mistletoe
European mistletoe (Viscum album) is an evergreen parasite
that depends on a host, often an old apple tree. It has long been considered
a sacred plant, partially because of its medicinal properties.8 Historically,
mistletoe was used to treat nervous disorders, but some European clinics are
now using it to treat cancer.
Mistletoe may prove helpful for treating cancer because it stimulates
the immune system, stabilizes DNA, inhibits blood vessel growth and is toxic
to cancer cells.9 Many of these effects were documented in cell and
animal studies in the 1970s and 1980s. Although small and poorly designed, some
human studies show that mistletoe treatment also improves the quality of life
and survival rates for people with cancer.
The most common preparation of mistletoe is an injectable, fermented
whole-plant extract called Iscador.10 Its active components include
proteins such as ML-I and viscotoxins. Recent studies show that mistletoe's
viscotoxins affect the immune system. Arndt Bussing from Krebsforschung Herdecke,
University Witten/Herdecke in Germany showed that crude extracts of viscotoxin
stimulated human granulocyte cells (a type of white blood cell) to destroy pathogenic
cells.11 This is especially important because cancer treatment stunts
granuloctye activity, which in turn increases infection risk. Treatment with
mistletoe must be administered only under the supervision of a health care provider.
Ginseng
There are two types of ginseng, Panax ginseng, also known
as Oriental, Asiatic, Chinese, Korean or Japanese ginseng, and P. quinquefolius,
known as American ginseng. Siberian ginseng (Eluetherococcus senticosus)
is a different plant genus entirely but shares many properties with true ginseng.
All of the ginsengs are adaptogenic herbs, meaning they produce nonspecific
resistance for the body. Although ginseng's energy-producing properties can
benefit someone with cancer, scientific evidence indicates it has more specific
uses.10
A recent cell study by Tadahir Takeda from Kanazawa University
in Ishikawa, Japan, showed that polysaccharides from panax boost production
of the immune-stimulating cytokine interleukin-8. Both leukemic human monocytes
(types of blood cells) and normal human monocytes were incubated with panax
extracts for 24 hours. Researchers then measured the amount of IL-8 in the cells.
The ginseng significantly increased the amount of IL-8 secreted from these cells
compared to cells not incubated with ginseng.12
A purified polysaccharide of panax, called ginsan, has several
immunomodulating effects on mouse cells that are similar to the effects of the
naturally occurring cytokine interleukin-2. Ginsan activates T and B lymphocytes
and macrophages and converts spleen cells into activated killer cells that destroy
tumor cells. When ginsan was injected into mice with induced lung cancer, it
significantly reduced the number of tumors--by 44 percent--compared with mice
that did not receive ginsan. When mice were given ginsan in their drinking water,
the tumors also decreased, but only by 15 percent. Ginsan had no detectable
toxicity.13
Customers should discuss using ginseng with their physician because
the herb can decrease blood platelet clotting. When taken in conjunction with
chemotherapy, bleeding problems may occur.
Astragalus
In Chinese medicine, astragalus (Astragalus membranaceous)
is considered an adaptogenic herb.14 A 1988 experiment indicated
astragalus extract increased the ability of interleukin-2 to kill cultured tumor
cells.15 A more recent study at the Hiroshima University School of
Medicine in Japan showed that a water-based astragalus extract, when incubated
with mouse spleen cells, had several immunopotentiating effects. It increased
B cell growth, T cell activity, and interleukin-6, tumor necrosis factor and
antibody production.16
Astragalus also protects the body against drug toxicity. In one
animal study, a combination of astragalus and wintergreen (Pyrola rotundifolia)
prevented damage to the kidney and to the cochlear nerves and hair cells of
the inner ear caused by the antibiotic gentamicin, commonly prescribed for pneumonia
and sepsis.17
Astragalus is included in a Chinese herbal medicine referred to
as 10 significant tonic decoction or SQT (Shi-Quan-Da-Bu-Tang). It is a 10-herb
combination recommended in conjunction with cancer therapy to protect the body
from drug toxicity and increase immunity. According to Chinese research, astragalus
prevents the adverse effects of the anti-cancer drugs mitomycin C and cisplatin
as well as stimulates the immune system.18 The herb is more commonly
used in Asia as an adjuvant to cancer treatments.
